New material and papers in the Green Space and Interviews pages, and a new Microbial Biodiversity page

New PNAS paper in the PSYCHIATRY page: immunising with an organism from the environment can oppose effects of stress.

This site provides rapid access to our latest thinking on the "Old Friends mechanism", a reformulation of the hygiene hypothesis as a crucial branch of "Darwinian" or "Evolutionary" medicine.

The pages that follow contain mostly recent publications, together with their abstracts, and links that will enable most of them to be downloaded.... when that is not possible, email me and I will send a copy if I can.

We discuss the evolutionary theory and immunological mechanisms behind the Old Friends mechanism, and point out the implications for human health and wellbeing in rich developed countries.

The current emphasis is on reduced stress resilience and the increased prevalence of depression in modern city-dwellers. We argue that this is at least partly secondary to defective immunoregulation attributable to the "Old Friends" mechanism.

A new extension of the Old Friends mechanism considers its role in the beneficial effects of living close to Green Spaces. See my recent review of this topic in Proc Natl Acad Sci USA (PNAS).... go to the Green Spaces page

There is also a new link to BBC Active. They offer educational BBC television programmes for use by Schools and universities. I took part in a programme in the BBC’s Horizon series with the title “Allergies- Modern Life and Me”. See more about this on the “Interviews” page of this site.

The pages first describe the "Old Friends" mechanism, and why this Darwinian concept usefully expands and corrects the original hygiene hypothesis, and increases its explanatory power in several clinical domains.

Then the site deals with the implications of faulty immunoregulation for psychiatry, and in particular for depression and stress resilience. It is postulated that one reason that depression is increasing is a reduction stress resilience in rich countries that has an immunological basis

Several of the papers refer to autoimmunity, but this page shows one that deals almost exclusively with this topic, and attempts to reconcile the many hypotheses about the recent increases in autoimmune disorders.

A failure of immunoregulation can lead to cancer, and also drive the cancer after it has developed. Inflammation drives mutation and provides angiogenenic factors, and tumour growth factors. The increase in the incidence of some cancers (such as prostate) parallels the increases in other chronic inflammatory disorders.

Exposure to green spaces improves physical and psychological health. The Old Friends mechanism provides a mechanism that can be documented by physiological measures relating directly to the disorders from which green spaces protect us. We may have evolved to need psychological input from the natural environment. But just as important, our immune systems have evolved to require inputs from biodiversity of the natural environment.

There are several recent interviews, all on the topic of the "Old Friends" mechanism and its clinical implications